Microfluidic chips are generally disposable devices due to the problems presented in reprocessing them for repeated use. Reuse of microchips can be impractical because of handling problems, buildup of reagent constituents in the chips, and the introduction of other variables with repeated use that can cause inconsistent results.
Microfluidic chips used in many microfluidic instruments are a small part of the overall instrument and can be relatively inexpensive. The automated manufacturing processes for microfluidic chips can reduce their cost and can provide consistent analytical results between runs on different chips. In many cases, microfluidic chips are considered “disposables” associated with microfluidic analyses. However, the cost of chips and the generation of waste in large microfluidic assay projects can add up to a significant expense. Moreover, there is much to be said for running comparative experiments on the same hardware.
Attempts have been made to wash and reuse microfluidic chips. Labs with small budgets and low labor costs have been known to manually wash chips. Chip makers have been known to manually wash microfluidic chip prototypes. Nevertheless, manual washing can be highly problematic. Manual microfluidic chip washing can proceed on a lab bench with a technician manually pipetting microliter wash solution volumes in and out of individual millimeter scale reagent wells, and flushing microchannels with syringes inserted through portals. However, problems often arise due to the uncontrolled environment and inconsistency of manual procedures. For example, particles in the environment can enter the chip and clog microchannels, bubbles can be unintentionally introduced into the chip, and use of reagents and accumulation of hazardous wastes can be excessive. Inconsistent manual processing can result in difficulty validating procedures and low confidence in results. The time, effort and expense of manual microfluidic chip reprocessing can be prohibitive.
Careful records should be maintained regarding the identification and use of reprocessed microfluidic chips so that the usable life of the chips is not unintentionally exceeded, possibly resulting in corruption of analytical results. Currently, the method typically employed for such record-keeping requires each individual user of the microfluidic device to maintain a detailed log listing which microfluidic chip is used, the purpose for which the device has been used, and the number of samples handled during use. This record-keeping method has several limitations. For example, a user may simply fail to record a use. Also, an identification label affixed to the surface of the microfluidic chip may become lost or illegible due to wet storage of the microfluidic chip, resulting in an inability to identify the microfluidic chip. If an identification label is affixed to the package for storing the microfluidic chip, the wrong device may be placed into the package.
In view of the above, a need exists for consistent, reliable and controlled methods to process microfluidic chips for reuse. It would be desirable to have systems that reduce the expense and waste involved in cleaning microfluidic chips for reuse. Benefits can be provided by systems and methods that efficiently and reliably track the use history of microfluidic chips. The present invention provides these and other features that will be apparent upon review of the following.